X-ray and γ-ray scintillators are important due to their extensive use in X-ray photography, X-ray phosphors, positron emission tomography (PET), computer tomography (CT) scanners, and, more recently, in large scale radiation detectors used at ports and border crossings. Currently used inorganic scintillators fall into two major groups, the ionic halides and covalent oxides. Depending on the intended application, sensitivity to different radiation sources is needed and most scintillators work best for only a single type of application. The application specific features for an ideal scintillator include a high light yield, a fast response time, high energy resolution, and chemical (moisture) inertness. Optimizing these features makes the development of new scintillators of continuing interest.